The present invention relates to a multi-chamber dispensing container for storing at least two substances which must be stored separately, the extemporaneous mixture thereof, and the dispensing of the mixture of these substances. The present invention will be more particularly described with respect to a dropper flask with two chambers, containing, sterile during storage, for example, a lyophilized powder in a first chamber, and a liquid in a second chamber, these two substances then being mixed extemporaneously in the container, and the mixture then being dispensed.
A multi-chamber dispensing container of the type mentioned hereinabove is known, described by International Patent Application published under No. WO-A-91/00094. This Application generally describes the use of a multi-chamber dispensing container for storing and, extemporaneously, dispensing a mixture of two liquids, in the present case a solution of papaverine sulfate and a basic solution such as bicarbonate of soda. It is necessary to separate the two solutions in order to prevent the precipitation of papaverine H during storage thereof. The two solutions are stored in a container body in the form of a rubber tube, presenting an end having an opening and a bottom end, in two chambers separated by a disc of plastics material. This disc is disposed perpendicularly to the container body and is of larger diameter than the inner diameter of the container body. In this way, the disc is maintained in place by the elastic hold of the container body on the peripheral edge thereof. Dispensing means are also provided in the vicinity of the end having an opening of the container body, hermetically closing said opening, and take the form of an injection needle. Before activation, i.e. during storage, the two liquids are therefore hermetically separated by the disc. Activation of the dispensing container is effected by a displacement of the disc caused by the pressure of the hand and thumb in a reciprocating movement on the body of the container. The disc is thus caused to drop into the bottom of the tube, and the two solutions can mix. The mixture is then dispensed by injection into the body through the needle.
However, such a container presents the following drawbacks:
the pressure necessary for displacing the disc in order to be able to mix the two substances is high, as the diameter of said disc is larger than the inner diameter of the container body, the disc being, moreover, positively retained in the body via an annular groove provided on the inner wall of said container body; PA1 once disengaged, the disc may move freely in the tubular body, and, during dispensing of the mixture by injection, the body is inverted, which causes the disc to block at least partially the exit of the mixture via the needle.